Scrambler C

[XJcwolfyX]

I saw a team on saturday attempt the bonus and still manage to get the car within 10-15 cm of the target. It was really crazy because they had the steering, angle of their launcher, and other factors all thought out and they executed it perfectly. Its gonna be impossible for my car to compete against them unless i get the bonus figured out.

Where was this? I think I may have seen the same one!

[sciolyscambler]

this was niles west invitation in illinois

[chinesesushi]

Top three scores from the Mira Loma Invitational were over 5000, which means they successfully completed the bonus. 2nd and 3rd place were the same schools. The ones that didn't attempt the bonus received scores just over 4960. 1st and 2nd place differed by <10 points.

[TTAWD]

So, how is Impound run in states across the country. Are the Scramblers tested for build rule compliance at impound and teams are allowed to make modification to the device before the end of impound or are the devices just impounded and compliance is tested when the teams show up for their runs? I ask this for several reasons. First, the rules this year state that "any materials to repair or to bring the scrambler into compliance must be impounded". Second, the scoring guideline say the an ES may allow the device to be brought up to spec. but not that they have to allow this. I can see this being allowed at a regional competition but state competitors should be held to a higher standard. The third reason is at our state competition last year, we had at least 20 schools that did not meet the rules, therefore impound was a zoo.

At our state tournament last year, devices were checked before impound, so teams with devices that did not comply with the rules could adjust their devices. However, at our state tournament two years ago, for Gravity Vehicle, I remember adjusting our ramp within our scheduled time because the supervisors did not check for compliance with the rules until teams tested their devices.

If we refer to the "Scoring Guidelines" page of the Soinc.org ( http://www.soinc.org/scoring_guidelines ), it appears to give us a pretty clear statement about adjusting a device and impound...It states:

"Event Supervisors may, at their discretion, allow students to modify any device before it is impounded to bring it into compliance with the rules. That discretion, if extended, must be made available to all competitors equally. Any modification must be completed, and the device impounded, before the expiration of the impound period. Supervisors and Officials may not provide assistance or advice regarding the type of modifications or how to accomplish them prior to, or at any time during the tournament day."

I feel that this makes sense. I believe that if teams can't even bother to spend the time or effort to carefully follow the written rules, then they should have their scores dinged accordingly.

Hope this helps to make things uniform and fair, for all!

[mcascienceolympiad1]

What type of wheels is everyone using besides CDs on the car? The CDs are flimsy and can break, even though they seem to be used the most.

[bernard]

What type of wheels is everyone using besides CDs on the car? The CDs are flimsy and can break, even though they seem to be used the most.

If you are using CDs for wheels, Servocity sells rubber tires that fit CDs well. I prefer buying Servocity's wheels, hubs, and shafts because they're made precisely so you have minimal amounts of friction when rotating and the wheels are naturally parallel when assembled. In the past I've bought bearings to reduce friction but I've found that with their 1/8" shafts, it's more efficient without bearings.

Buying their wheels ($20 for four hubs, $1 for a shaft/axle, about $10-15 for four wheels depending on size) is more expensive than making your own CD wheels but having gone through the frustration of making perfect wheels, paying more is worth it.

[InfiniCuber]

I have a question in regards to the spring launchers. I have a "spring" launcher system for my scrambler (it isn't a spring, it's a kind of stretchy rubber), and the fastest time ive been able to get while practicing was 1.7 sec. The reason i say 'while practicing' is because for some reason at my last competition last week, the EC's got my times (out of three) to be 1.3, 1.4, and 1.5(about) which is WAY quicker than we anticipated. My guess is human error, as I was expecting the use of a photo gate system. Back to my main point, I've seen people say they have been able to get 1.2 sec (and one instance sub 1) on their runs using a spring launcher. Any ideas on how to increase my times? (Also I posted a response around page 4 of this thread, claiming I had gotten 1.2 sec with a simple pulley system (no spring), which is completely wrong. My memory failed me, I believe once we got 1.9 sec once, but our car was around 2-2.2 seconds. Anyways, sidetracking again...) So how can I go faster? Should I actually use a spring?

[bernard]

I have a question in regards to the spring launchers. I have a "spring" launcher system for my scrambler (it isn't a spring, it's a kind of stretchy rubber), and the fastest time ive been able to get while practicing was 1.7 sec. The reason i say 'while practicing' is because for some reason at my last competition last week, the EC's got my times (out of three) to be 1.3, 1.4, and 1.5(about) which is WAY quicker than we anticipated. My guess is human error, as I was expecting the use of a photo gate system. Back to my main point, I've seen people say they have been able to get 1.2 sec (and one instance sub 1) on their runs using a spring launcher. Any ideas on how to increase my times? (Also I posted a response around page 4 of this thread, claiming I had gotten 1.2 sec with a simple pulley system (no spring), which is completely wrong. My memory failed me, I believe once we got 1.9 sec once, but our car was around 2-2.2 seconds. Anyways, sidetracking again...) So how can I go faster? Should I actually use a spring?

What is the mass of your ETV? Have you tried lowering the mass of that? If not and your ETV is heavy, what materials are you using and are there alternatives available that are lighter?

Have you tried springs of different lengths and spring constants? Is your spring constant as high as possible so the 2 kg mass is just able to stretch it (and any higher spring constant would result in the mass not falling all the way)?

[InfiniCuber]

What is the mass of your ETV? Have you tried lowering the mass of that? If not and your ETV is heavy, what materials are you using and are there alternatives available that are lighter?

Have you tried springs of different lengths and spring constants? Is your spring constant as high as possible so the 2 kg mass is just able to stretch it (and any higher spring constant would result in the mass not falling all the way)?

The mass is about 380 grams. Yes I've tried lowering it, its rather difficult at my stage tho. I'm using a bit of plastic and carbon so they are relatively light materials. Yes I have tried differing lengths and k values for my elastic band, and my set up has it so that at the very bottom of its stretch which is pretty much a full meter it releases all the energy. Idk what to do more!

[iwonder]

The mass is about 380 grams. Yes I've tried lowering it, its rather difficult at my stage tho. I'm using a bit of plastic and carbon so they are relatively light materials. Yes I have tried differing lengths and k values for my elastic band, and my set up has it so that at the very bottom of its stretch which is pretty much a full meter it releases all the energy. Idk what to do more!

Check you PM, infinicuber.

Also, what kind of bearings do you have and how well do your wheels spin freely in the air?